From 44e148de380872c47628195c0dea8477b921082b Mon Sep 17 00:00:00 2001
From: Aadi Desai <21363892+supleed2@users.noreply.github.com>
Date: Sun, 28 May 2023 16:04:18 +0100
Subject: [PATCH] Add saw2sin.sv

Handles inversion and reversing to create full sine wave from quarter wave
---
 saw2sin.sv | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 saw2sin.sv

diff --git a/saw2sin.sv b/saw2sin.sv
new file mode 100644
index 0000000..f3aee26
--- /dev/null
+++ b/saw2sin.sv
@@ -0,0 +1,29 @@
+`default_nettype none
+
+module saw2sin
+( input  var [15:0] i_saw
+, output var [15:0] o_sin
+);
+
+logic invert;
+always_comb invert = i_saw[15];
+
+logic reverse;
+always_comb reverse = i_saw[14];
+
+logic [15:0] qsaw;
+always_comb qsaw = reverse
+  ? {~i_saw[13:0], 2'b01} // Reverse
+  : {i_saw[13:0], 2'b00}; // Normal
+
+logic [15:0] qsin;
+cordic cordic
+( .i_qph (qsaw)
+, .o_sin (qsin)
+);
+
+always_comb o_sin = invert
+  ? ~{1'b1, qsin[15:1]} + 1 // Invert
+  : {1'b1, qsin[15:1]};     // Normal
+
+endmodule